Weather and traffic accidents in Hong Kong

The influence of rainfall and thermal stress in accident occurrence for the period 1985 through 1994 in Hong Kong was investigated. The existence of seasonal variations and weekly cycle was also examined. Daity accident and meteorological data were obtained from the Transport Department and the Hong Kong Observatory respectively. Utilizing regression analyses and ANOVA, it is discovered that seasonal variation was not important in contributing traffic accidents, and Saturday peak was not ascertained. A non linear relationship between accident occurrence and various rain conditions was found. Accident numbers increased till rain exceeded 50.0 mm. High traffic volume and low speed urban driving in Hong Kong can be the major cause of traffic accidents on rainy days. The impact of heat stress on accident occurrence was found to be statistically significant.